I rather akin this to the car dealership's service department or quick lube place telling you that your oil needs to be changed every 3,000 miles when your Factory Service manual recommends 6,000.
Take a peek at your oil change sticker - if the interval is less than what is recommended for your vehicle.. take note.
(BTW - I'm a former Service Director for a car dealership.)
Unless you have an older model vehicle or drive in extreme conditions... that 3K oil change is just lining the pockets of the owners. ;)
Just like the suggestion to buy new thread is for the shop owner.